Ensure to get also deleted entries in belongs_to assoc.

app/models/article.rb

@@ -7,7 +7,7 @@ class Article < ActiveRecord::Base
   localize_input_of :price, :tax, :deposit
 
   # Associations
-  belongs_to :supplier
+  belongs_to :supplier, :with_deleted => true
   belongs_to :article_category
   has_many :article_prices, :order => "created_at DESC"
 

app/models/article_price.rb

@@ -1,6 +1,6 @@
 class ArticlePrice < ActiveRecord::Base
 
-  belongs_to :article
+  belongs_to :article, :with_deleted => true
   has_many :order_articles
 
   validates_presence_of :price, :tax, :deposit, :unit_quantity

app/models/delivery.rb

@@ -1,6 +1,6 @@
 class Delivery < ActiveRecord::Base
 
-  belongs_to :supplier
+  belongs_to :supplier, :with_deleted => true
   has_one :invoice
   has_many :stock_changes, :dependent => :destroy
 

app/models/financial_transaction.rb

@@ -1,7 +1,7 @@
 # financial transactions are the foodcoop internal financial transactions
 # only ordergroups have an account  balance and are happy to transfer money
 class FinancialTransaction < ActiveRecord::Base
-  belongs_to :ordergroup
+  belongs_to :ordergroup, :with_deleted => true
   belongs_to :user
   
   validates_presence_of :amount, :note, :user_id, :ordergroup_id

app/models/group_order.rb

@@ -4,7 +4,7 @@ class GroupOrder < ActiveRecord::Base
   attr_accessor :group_order_articles_attributes
 
   belongs_to :order
-  belongs_to :ordergroup
+  belongs_to :ordergroup, :with_deleted => true
   has_many :group_order_articles, :dependent => :destroy
   has_many :order_articles, :through => :group_order_articles
   belongs_to :updated_by, :class_name => "User", :foreign_key => "updated_by_user_id"

app/models/invoice.rb

@@ -1,6 +1,6 @@
 class Invoice < ActiveRecord::Base
 
-  belongs_to :supplier
+  belongs_to :supplier, :with_deleted => true
   belongs_to :delivery
   belongs_to :order
 

app/models/order.rb

@@ -10,7 +10,7 @@ class Order < ActiveRecord::Base
   has_one :invoice
   has_many :comments, :class_name => "OrderComment", :order => "created_at"
   has_many :stock_changes
-  belongs_to :supplier
+  belongs_to :supplier, :with_deleted => true
   belongs_to :updated_by, :class_name => 'User', :foreign_key => 'updated_by_user_id'
   belongs_to :created_by, :class_name => 'User', :foreign_key => 'created_by_user_id'
 

app/models/order_article.rb

@@ -4,7 +4,7 @@ class OrderArticle < ActiveRecord::Base
   attr_reader :update_current_price
 
   belongs_to :order
-  belongs_to :article
+  belongs_to :article, :with_deleted => true
   belongs_to :article_price
   has_many :group_order_articles, :dependent => :destroy